Source: Head-Olfactory Nerve image, Creative Commons: http://commons.wikimedia.org/wiki/File:Head_olfactory_nerve.jpg; Taste Bud image, Creative Commons: http://commons.wikimedia.org/wiki/File:Taste_bud.svg;
Special senses that are detected by highly specialized, chemical receptors (olfaction and gustation) that detect dissolved chemicals and gases; olfactory and gustation receptors are encapsulated nerve endings that are embedded with mucous membranes (olfactory) or muscle & epithelial tissues (gustation).
Receptors embedded within the mucous membranes of the nose that are specialized in detecting odor molecules/various odors; encapuslated nerves that synapse with the olfactory bulb on the superior/upper aspect of the roof of the nose.
Encapsulated receptors found within taste buds; taste buds are located on lingual papillae on the tongue, in the roof of the mouth and your throat; there are 5 different tastes that human taste buds are capable of detecting.
Foods that are naturally rich in carbohydrates elicit the sensation of sweetness; there are also artificial compounds designed to stimulate sweetness (artificial sweeteners).
Foods that are rich in salts/minerals elicit the sensation of saltiness (sodium, calcium salts, etc).
A perception of taste triggered by acidic foods (example: citrus fruits).
A perception of taste often associated with spoiled or undesirable foods (examples: sour milk, nicotine).
A perception of taste triggered by amino acids and is often associated with savory foods (example: meat).